Why Is Selenium a Recommended Supplement to Take?

Exciting news, my book is finally here! New to learning about your thyroid health? Learn why it's important to be your own health advocate in my book now. Available on Amazon

This post may contain affiliate links, to find out more information, please read my disclosure statement.

Originally published on 20th May 2016Last updated on 6th August 2019

Selenium is a trace mineral found in food and soil, which is vital for immune response and thyroid function, including conversion of thyroid hormone T4 to T3, making it essential for good metabolic function. It is often recommended that those of us with hypothyroidism and Hashimoto’s consider supplementing Selenium. So, should you?

Selenium for Conversion

A lot of people with hypothyroidism have trouble converting their T4 medication to the active thyroid hormone T3, so a lack of the protein iodothyronine deiodinases (which selenium is needed for) could be the reason. A sign being that if you’re on T4-only medication, such as Levothyroxine or Synthroid, and not feeling any better, especially if your thyroid blood test results look ‘OK’ or you’re low in Free T3, then you could be low or deficient in iodothyronine deiodinases, and therefore, selenium. Selenium is very important for conversion.

A study published in 2002 discussed selenium’s affect on thyroid antibodies. The researchers reported that they gave 200mcg of sodium on a daily basis to Hashimoto’s patients with high levels of TpoAB. After three months, their levels were redrawn and a decrease of the TpoAB value by 66.4% was found.

How Much?

The NHS recommend a conservative 0.06mg a day for women and 0.075mg a day for men and Dr. Axe recommends no more than 0.055mg a day, which is more or less in line with NHS recommendations.

However, the recommended dose by many thyroid sources is 200mcg a day, such as STTM and Thyroid Pharmacist Izabella Wentz who both also promote taking 200mg a day. The study mentioned above also used this amount.

As we don’t yet know the potential risks of long-term supplementation of Selenium, the safest option may be to meet requirements by eating selenium rich foods like: brazil nuts, cod, tuna, mushrooms and meats. Brazil nuts are usually considered the most popular option, with just two to three of them a day providing roughly 0.2mg of selenium. But they need to be organic, preferably, and of very good quality, to contain the selenium you require. It can be hard to determine if they contain enough, which is why so many people prefer to just supplement instead.

If you do want to supplement, then organic forms of selenium, such as selenium yeast or selenomethionine, are said to be safer and more easily absorbed, and as with most supplements, selenium can have toxic effects when used in excess, so be aware. Symptoms of selenium toxicity include diarrhoea, hair loss and brittle nails.

If in doubt, test your selenium levels before you start supplementing, to ensure you don’t over-do it by taking too much and discuss taking any new supplements with your doctor.

Has supplementing selenium helped you?

You can click on the hyperlinks in the above post to learn more and see references to information given.

If you found this article beneficial, please take a moment to share it so we can help others get better with hypothyroidism and Hashimoto's, whilst also raising awareness. "Be Your Own Thyroid Advocate."